1. Field of the Invention
This invention relates to a ball cock construction of the type used for the control of liquid levels in tanks. More specifically, the invention relates to an improved ball cock assembly for use in the flush tank of a toilet or the like, and an adjustable riser to use with the ball cock assembly.
2. Discussion of the Prior Art
A conventional ball cock assembly includes an inlet tube that allows water under pressure to flow into a flush tank through a float operated ball cock valve mounted atop the tube above the normal water level. An outlet tube extends downward from the valve so that when the float operated valve is open, water will flow into the outlet tube and then into the flush tank. The ball cock valve controls the operation of the ball cock assembly, and must be constructed to provide reliable operation through thousands of flush cycles. Therefore, it is desirable to use a ball cock valve which is of rugged construction, and which is substantially fail-safe.
Toilet tanks are made in many different sizes and shapes, and in many different heights. The ball cock assembly is mounted at a height commensurate with the height of the tank. Upon failure of the assembly for any reason, it is common to obtain a replacement assembly which is properly sized for the tank, or which can be quickly and securely adjusted to different lengths according to the tank size.
U.S. Pat. No. 4,100,928 describes a valve assembly for a ball cock valve including a riser having telescopically adjustable concentric inlet and outlet tubes. Each of the concentric tubes is composed of an upper and a lower member. Adjustment of the tubes is achieved by the use of a continuous spiral grooves or a plurality of discrete, spaced apart grooves on one member and a plurality of fingers at the end of the second member, each with radially inwardly extending projections. The riser includes a lock collar which slips over the end of the fingers and when threaded into place, flexes the fingers inwardly to urge the projections into the grooves. The deflection of the fingers during assembly or adjustment of the riser increases the likelihood of breaking one of the fingers. The height of the riser is adjusted by unscrewing the lock collar to release the projections from the groove, and manually telescoping the two tubes to the required height followed by threading the lock collar over the fingers to force the projections into engagement with a corresponding groove.
The ball cock construction typically comprises a valve seat disposed between an inlet and a plurality of liquid outlets spaced circumferentially around the inlet, a resilient valve seal, a valve cover and a pilot valve pin extending through the cover and valve seal. The typical ball cock construction can utilize a siphon arrangement to prevent back flow of water in the event of a total or substantial drop in the pressure of the incoming water.
U.S. Pat. No. 4,108,202 likewise describes a ball cock with a vertically adjustable outlet tube. In the manner similar to that described in U.S. Pat. No. 4,100,928, two telescoping members which comprise the outlet tube of the riser are provided with grooves, either spiral, or discrete vertically spaced on one of the members, and projections on the end of the other member, adapted to engage the grooves. The projections are at the end of flexible fingers which are flexed radially inwardly to engage the grooves, and are held in the grooves by a threaded lock collar. To make the height adjustment, the collar must be threaded one way to release the fingers from the groove, and then threaded the other way to re-engage the projections with the groove.
U.S. Pat. No. 4,182,364 likewise describes a vertically adjustable riser which contains circumferential grooves on one member and resilient fingers with inward projections to be locked into one of the grooves. The fingers are at the upper end of the outer member and have gaps between them allowing inward deflection. A lock collar is threaded on to the upper end of the outer member and as the member is progressively tightened, deflects the projection into engagement with the groove. To adjust the vertical height of the riser, the collar must be unscrewed to release the deflected projections from the groove.
U.S. Pat. No. 4,703,653 describes a plastic ball cock float structure of the general type useful in the present invention. The float contains a vertical channel adapted to receive the riser. The float moves up and down on the riser in response to changes in the water level in the tank, thereby closing and opening a water inlet valve.